Export armature DAE -> glTF rotates mesh 90 degrees
The solution was to upgrade Blender from 2.82. 2.83 had big improvements in skinning for the glTF importer.
By the way, if you ever have issues with how a skinned mesh looks in edit mode, you can also try toggling the &quot;Guess Original Bind Pose&quot; option on the glTF import screen.